Rebel Wilson has welcomed a baby girl via a surrogate.

The 42-year-old actress - who is in a relationship with designer Ramona Agruma - has taken to Instagram to announce the arrival of her first child.

In a heartfelt post, Rebel shared: "Beyond proud to announce the birth of my first child, Royce Lillian, born this past week via surrogate [heart emoji]

"I can't even describe the love I have for her, she's a beautiful miracle! I am forever grateful to everyone who has been involved, (you know who you are), this has been years in the making…but particularly wanted to thank my gorgeous surrogate who carried her and birthed her with such grace and care. Thank you for helping me start my own family, it's an amazing gift.The BEST gift!! (sic)"

Rebel also revealed that she's already "learning quickly" about the challenges of motherhood.

Her post continued: "I am ready to give little Roycie all the love imaginable. I am learning quickly…much respect to all the Mums out there! Proud to be in your club. [heart emojis] (sic)"

The 'Bridesmaids' star went public with her relationship with Ramona in June.

Alongside a photo of them together, Rebel said at the time: "I thought I was searching for a Disney Prince … but maybe what I really needed all this time was a Disney Princess [heart and rainbow emojis] #loveislove (sic)"

What's more, Rebel previously revealed that she embarked on a weight-loss journey in a bid to have children one day.

Recalling a meeting with her fertility doctor in 2019, Rebel shared: "I was carrying around a lot of excess weight. It's almost like I didn't think of my own needs. I thought of a future child's needs that really inspired me to get healthier."